SsangYong Korando III (2010 year). Manual — part 235

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4890-00

4WD - Front/Rear wheel speed

sensor

2WD - Front wheel speed sensor

2WD - Rear wheel speed sensor

ECU (Electronic Control Unit)

1.

ECU calculates the wheel speed, acceleration and

deceleration with the information from wheel

speed sensor, and determines the wheel slip to

control the valve and motor.

HU (Hydraulic Unit)

2.

The hydraulic circuit contains the primary circuit

and secondary circuit for ABS operation. This unit

controls the hydraulic pressure to each wheel. If

the system needs ABS operation, the valves in

the unit operate to control HOLD, RISE and

DUMP according to ECU control logic.

Motor

3.

The motor is operated when ABS is activated. The

cam-shaped output shaft of the motor enables the

brake system to receive and supply the brake fluid

during the motor operation.

Wheel speed sensor

▶

Wheel speed sensor sends the data detected by

tone wheel to HECU.

HECU

▶

Rear wheel speed sensor in 2WD vehicle is

different from that in 4WD vehicle.

Location of rear tone wheel (A) and wheel

sensor (B) in 2WD vehicle

10-8

G-sensor (only for 4WD)

▶

For the vehicle with the ABS, a speed difference

between the wheels is not noticeable as all the

wheels are slipping during abrupt braking.

Therefore, the vehicle needs the speed

information from other sensors other than the

wheel speed sensor. On the 2WD vehicle, there

is not large difference between the vehicle speed

reduction and actual wheel speed reduction in

the event of braking since the driving wheels are

in the front. So, the ABS HECU can control the

vehicle, based on a calculation value. But, on the

4WD vehicle, if a speed reduction occurs in the

front or rear of the vehicle, it affects the other side

wheel. In other words, braking the rear wheels

induces also a large speed reduction in the front

wheels. The longitudinal acceleration sensor is

used for this case. It controls the ABS by using

the signals from the sensor during abrupt braking

and acceleration.

G-sensor

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3. ABS CONTROL LOGIC

The principal ABS control logic is the determination of the reference speed by choosing one wheel

meeting a certain condition, while sensing the speed information from 4 wheel speed sensors when the

vehicle is being driven.

For example, when the comparison of the reference speed with front right wheel speed shows a slip, the

control signal is determined according to whether it's deceleration or acceleration. If the control

conditions are met, the brake for the front right wheel will be got under control.

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4. WARNING LAMPS

1) ABS Warning Lamp

ABS warning lamp module indicates the self diagnosis and malfunction.

ABS warning lamp ON:

When turning the ignition switch to ON position, ABS warning lamp comes on for 3 seconds for self-

diagnosis and goes off if the system is OK (initialization mode).

When the system is defective, the warning lamp comes on.

When the self-diagnosis is performing, the warning lamp comes on.

When the HECU connector is disconnected, the warning lamp comes on.

ABS is not available during lamp ON. In this condition, Only normal brake system without ABS function

is available.

When the communication between warning lamp CAN module in meter cluster, the warning lamp

comes on.

1.

2.

3.

4.

5.

6.

ABS warning lamp

Brake warning lamp

(EBD warning lamp: ABS warning lamp + Brake warning lamp)

1.

2.